1. Field of the Invention
The present invention relates to a frame structure of a fork lift truck including a steering axle assembly provided with a pair of pivots longitudinally spaced from each other by a given distance and defining a longitudinal axis about which steering axles are adapted to swing.
2. Description of Prior Art
Conventional frame structure for such a fork lift truck will be explained with reference to FIGS. 1 to 3. The rear frame structure 1 includes a horizontal plate member 3 provided on its lower surface with longitudinally spaced projections 2 which define recesses for receiving the pivots of the steering axle assembly. A rear plate member 4 is secured to the upper surface of the horizontal plate member 3 and projected therefrom generally perpendicularly. Mounting plate members 5 are provided whose rear ends 6 are secured to the rear plate member 4. The mounting plate members are further secured on their lower edges to the horizontal plate member 3. Longitudinally extending side panels 7 on their rear ends 8 are secured to the side edges of the rear plate member 4. The side panels 7 are formed with lower surfaces 10 to which a rear cross member 11 is secured. The front ends 9 of the mounting plate members 5 as well as the front end of the horizontal plate member 3 are welded to the rear surface of the cross member 11. A box section member 12 is secured to the lower surface of the side panel 7, and to the cross member 11 on its rear end. A cover 13 is pivotally mounted to the box section member 12 by a hinge, not shown, so as to be opened or closed. The cover is held by a locking means, not shown, in contact with, or near a shoulder portion 14 of the side panel. A battery assembly 15 is placed on the lower portion of the side panel 7.
When various types of fork lift trucks having different wheel bases are to be manufactured by using a standardized steering axle assembly of the type mentioned above, the position of the projections 2 for mounting the axle assembly has to be adjusted longitudinally of the frame structure. However, since the front ends of the horizontal plate member 3 and of the mounting plate members 5 are brought into abutting engagement with, and welded to the rear cross member 11, at the time of assembling the frame structure, the position of those members cannot be adjusted longitudinally. Thus, the position of the mounting projections 2 has to be adjusted longitudinally with respect to the horizontal plate member 3 for each type of the fork lift truck. This means that various types of assembly jigs have to be prepared, which require a substantial expense. Moreover, since the members forming the rear portion of the frame structure, including the mounting projections 2, cannot be integrated into a standardized assembly which may be used to any types of fork lift trucks, assembling works of the frame structure cannot readily be simplified.